NixOS is a Linux distribution with a unique approach to package and configuration management. Built on top of the Nix package manager, it is completely declarative, makes upgrading systems reliable, and has many other advantages. Nix package manager distributes build instructions for all Haskell packages registered on Hackage.

This is pretty much the same as Debian, providing you add the 'universe' and/or 'multiverse' repositories, which import Debian packages and recompile them to match Ubuntu dependencies. The exact versions of packages may be different from Debian, but they tend to be ahead of Debian stable (sometimes by a long way).
(See also How to install Haskell Platform for Ubuntu 13.04?)